As Aaron Gwin put it on his social media accounts – the secret’s out. The secret to flat protection that is. But that’s just the beginning. Flat Tire Defender is a new product out of Arizona that is the brain child of tire legend, Frank Stacy. Three years in the making, the foam inserts have already found their way to the top step of the World Cup podium and seem to be ready for their big debut. Similar in concept to technology that’s been used in motocross tires for years, the Flat Tire Defender is an ovalized foam insert that sits inside a standard tubeless or tubeless ready tire. Made from closed cell foam rubber, the inserts are airless meaning they should be fairly easy to install and won’t absorb sealant or lose their protective abilities…

Even though Gwin can literally ride the tires off a bike, it seems like keeping the air inside is best. While preventing flats is a big part of the FTD kit, Gwin claims it also leads to better handling with lower tire pressures possible with less sidewall rollover and minimized damage to rims and tires. Available to fit multiple wheel and tires sizes, kits include two rim strips, two tire valves, and zip ties for the installation procedure (below). Starting with 26″ trail and enduro bikes at $109.50 for the set, prices top out at $129.50 for the 29+ kit.

Installation is fairly straight forward with the tubeless valve installed normally, then the foam rubber strip placed on top with the tire sitting on either side. It does look to be a good bit tighter than a typical tire installation hence the zip ties, but overall looks to be pretty simple.

If FTD delivers on all its promises, this could be a huge step forward for mountain biking.


  1. This is basically very similar in concept to Schwalbe’s ProCore system. Unless it’s lighter and/or cheaper is there really any advantage one way or the other?

  2. Santanas, it’s sctually much more like the Huck Norris. Except it appears to be a closed closed foam. So it will be lighter then that. And it won’t require a proprietary rim or drilling like schwable.

      • It is like Huck Norris in that it is a closed cell foam insert, but is more like Procore in terms of where it sits inside the tire casing, and that is presses outward on the beads, preventing burping. The Huck Norris sits higher up, at the widest part of the tire and well above the bead area, and therefore does not offer the advantage of securing the bead more firmly against the rim.

        • And gtluke is right, while the prototype versions of Procore used 2 valves, Schwalbe switched to a single valve with a switch mechanism to selectively inflate either of the chambers.

  3. Sounds like a great product but it’s way too expensive. There’s no way R&D plus manufacturing expenses force them to price closed cell foam tubes like this.

  4. Keep coming with the clueless comments guys. Very entertaining. Stick to gravel road bikes or whatever is your niche. DH products like FTD, Procore, and Huck Norris seem to be over your heads.

    • Why would this be “barely rideable?” The weight is similar to running tubes. Check out their website. They show how they test rolling resistance with and without the tubes and how much more impact can be absorbed before denting the rim and pinching the casing. Very convincing data. No marketing claims, just posted scientific testing. Not sure why they don’t post that info here and on PB?

      This product makes perfect sense. So simple and easy to understand. Best product in a while. Too bad they are ripping us off with msrp.

  5. i never get these tricks. Everyone keesp syaing you can run lower pressures and yet when I run lower pressures the tire gets so squirmy I hate it. At the end of the day I save money weight and trouble because I don’t like lower pressure. Maybe someday someone will explain to me how to lower the pressure without getting a sloppy squirmy ride.

  6. I thought this video had some very valuable advice… always check to make sure that when you inflate a tire to 35 psi it doesn’t magically jump to 65 psi… duh, why hadn’t I thought of that!

    Cereal though, seems like a product with some potential…. I have a few customers in mind that I would make this mandatory for if it works as well as they claim

  7. So turns out you can create a similar system using closed cell air conditioning foam insulation, I’ve been riding on it for about a week and it feels great, about the same as all the claims about increasing damping and such. If anyone is interested in getting setup with a similar system to CushCore or Flat Tire Defender for under $15 as opposed at least $100 for those systems, let me know and I can create a DIY video. It seems to good to be true, and my DIY version may be 70% of what the big guys are producing, but if you can get 70% of the performance for about 12% of the cost, totally worth it.

  8. Try thick-walled mid-density foam pipe insulation with a medium-width innertube running inside (e.g.use a hybrid or road 700c tube for 29″ wheels if necessary. A bit of a b***h to install but once you have it on it seems to last well, feels good (rides well) even at lower-than-normal pressures, gives good puncture protection against glass, flints, sidewall slashes, short thorns. Good rim protection and fair run-flat protection. Costs $3, weighs 150g plus weight of tube but no sealant required. You can get pipe insulation in many different widths, so this works well for all rim diameters and tire widths. Use overall insulation diameter a few mm less than the tire width as the inner tube will cause it to expand to fit the gap. Too wide and you won’t be able to get it on.
    I have done BMX, CX, hybrids, enduro and downhill tyres like this and prefer it to tubeless for cost, hassle, durability and effectiveness against flats.

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